Ring circuit



2 Sheets-Sheet 1 T.A. PRUGH RING CIRCUIT July 25, 1950 Filed June 16, 1945 July 25, 1950 Filed June 16, 1945 T. A. PRUGH RING CIRCUIT SWITCH SWITCH SWITCH 2 sheets-sheet 2 FIGURE 2 THOMAS A. PRUQH INVENTOR @WMQ/u ATTORNEY ring stage.

Patented July 25, 1950 OFFICE RING CIRCUIT Thomas A. Prugh, United States Army, lArlington County, Va.

:Application June 16, 1945,;seria1 massen/is (Grasa- 27) (Granted vunder the act -of March, 1883, as

Claims.

amended 'Aprl '30, 192,8; 310 0. gG. y757) lTheinvention-described-herein may be manufactured and used'byforfor the Government for governmental purposes,-without theepayrnent to me of any royalty thereon.

This invention is in electrical apparatus and particularly in electronic ring circuits.

The principal'object ofthe invention is to pro videmeans for readilyreversing'the directionof :conduction of an electronic ring circuit.

Another object is to provide novel means for preventing successive conduction of the tubes of a ring circuit.

Other objects will be apparent from a reading of` the 4following specification/and claims.

In the drawings:

Figure `1 isra simplifiedwiring diagram of a portion of a conventional ringcircuit such as may lbe modified in accordance with my invention.

Figure 2 is a block diagram of the principal elements of the invention.

Figure 3 is a schematic diagram of the present invention.

In general, a ring circuit, such as is to be controlled by the present invention, consists of two or more vacuum tube stages interconnected as shown in Figure l. The circuit is so designed that each stage in turn delivers a positive or negative peaked output to the next. In the present description, the ring circuit will be assumed to be controlled by negative pulses.

Normally, one tube, I0 for example, is conducting, whereas II and I2 are cut oi. A negative trigger pulse applied tothe three tubes simultaneously over line 2|] causes tube I to cut 01T, whereupon the positive voltage developed at its plate, applied through a differentiating circuit to the grid of tube I I, produces conduction in the latter tube, this process being continuable as long as triggering pulses are supplied, the next negative pulse, it will be understood, cutting oi tube II and thereby producing conduction in tube I2.

Referring to Figure 2, the blocks, I0, I I, and I2, represent (just as in Figure 1) three stages of a conventional ring circuit; I3, I4, and I5, electronic means for controlling the conducitivity of the ring stages; and I6, I'I, and I8, switching means which determine the mode of action of the control stages, IS, I4, and I5.

To control the order in which the tubes Ill, Il, and I 2, conduct, a control stage is used with each Each control stage, as I3, consists of two cathode follower circuits in the form of a double triode, 24, see Figure 3. The common cathodes of tube 24 are connected to the input of ring tube I0 through a differentiating circuit.

. 2 The plate ofthe preceding ring stage, I2', is con:- nected through a differentiating Acircuit and-limitingresistorr 25 to the grid, '26, of double triode 24, and grid'l is similarly connected to the plate of-ring stage II.

Switch IS, controlling the plate bias o-ftubes 24,28, 2S, and 3i), is adapted for connection to one plate of each tube when in one position, and the other plate of each tube when in its second position. Switch I6, in other words, in this figure vreplaces the several switches I6, I'I, and I8 -of "Figure 2, it being quite permissible to control the switch tubes individually or as a group. The output of tube 24 is taken directly across `'the cathode resistor, 30. A positive pulse applied toagrid ofthe tube will, therefore, providedthe corresponding plate is properly biased, cause an increasein current flow through the cathode resistor and 'a corresponding voltage increase.

'When the cathode follower circuit is used to control a ring circuit, tubes 24, 28, 29, and 3B are biased nearly to cut oi through their respective cathode resistors. Plate voltages are varied through switch I6 from positive to zero. To cause the ring to conduct in a normal or forward direction, one plate of each of the double diodes (as 36 of tube 24) is made positive and the other plate (as 3i in tube 24) is zero.

Assuming a succession of conventional negative triggering pulses to be applied to the circuit of Figure 3, and the ring to be operating, as, for example, tube Il of the ring circuit begins to cut 01T, the differentiated positive pulse developed through capacitor 4i) and resistor 4I produces conduction in control tube 28 and thus drives the grid of tube I l more positive than before. The same pulse is, of course, furnished to grid 42 of control tube but there is no change in cathode voltage at this point since plate 43 of control tube 30 is at zero potential, and grid current ow is prevented by the limiting resistor, 44. When the grid of ring tube II goes positive, the tube conducts. As it cuts off on the next triggering pulse, it applies a positive pulse to grid 45 of control tube 29, causing tube I2 to conduct.

To reverse the order in which the tubes of the ring circuit begin conducting, switch IIB, controlling the cathode followers, is thrown, thus applying positive voltages to those plates of the control tubes which earlier were assumed to be at zero potential and bringing to Zero those which were earlier described as positive.

To stop the action of the ring circuit in any one condition, switch It is opened, assuring that no control tube can conduct, and thus no pulse can be transferred from one ring tube to another.

The foregoing description is in specific terms, and many modications will readily suggest themselves. Obviously, for example, two separate tubes properly connected are the full equivalent of the double tubes indicated. The inven- A circuit thereby to produce conduction in said tion should not, in other words, be considered 4as f limited to the exact apparatus shown and Aclescribed, but, instead, for the true scope thereof, reference should be had to the appended claims.

I claim:

1. A circuit for controlling a ring circuit of 11. y

stages, including n control stages in the nature of double triodes each control stage being so associated with a ring stage that variations in its conductivity produce variations in the conductivity of its ring stage, means for supplying the output of a conducting ring stage to one half of a control stage preceding and to one half of a control stage succeeding the control stage associated with the conducting ring stage thereby to vary the conductivity of a further ring stage.

2. A circuit for controlling a, ring circuit including a double triode or the like, means for applying different voltages to the plates of said triode, means for applying the output of said triode to a selected tube of the ring circuit thereby to vary the conductivity of said selected tube,

means for associating each of the grids of said selected tube, and means for associating each of the grids of said triode with a different unselected ring tube whereby conduction of a ring tube will vary4 the bias on one grid of said triode,

fl. A circuit for controlling a ring circuit including a control stage in the nature of a double vtriode associated with each ring stage, means for applying different voltages to the two plates of each of the control stages, means for applying simultaneouslyto the grids of the control stages preceding and succeeding the stage associated with a conducting ring stage a pulse from said last mentionedv ring stage to cause conduction in one control stage and thereby conduction in its associated ring stage.

5. A circuit for controlling a ring circuit of n stages, including n control stages in the nature of double triodes having common cathodes and plates which may be individually biased, each control stage being associated with a ring stage for the control thereof, means for supplying the output of a conducting ring stage to one grid veach of the controlstage preceding and succeedf ing the control stage associated with the con- REFERENCES CITED The following references are of record in the le of this patent:

UNTTEDJ STATES PATENTS Number Name 'l Date 2,158,285 KOCh v May 16, 1939 2,272,070 Reeves a Feb. 3, 1942 

